基于零序电压分布特征的小电流接地故障测距初探

Fault location of a small current grounding fault based on distribution characteristics of zero sequence voltage

故障测距能够大大提高故障巡线与修复速度,但现有配电网小电流接地故障测距技术存在经济性较差的问题。为此,提出一种基于零序电压分布特征、可在现有配网自动化系统上实现的小电流接地故障测距方法。首先,利用小电流接地故障分布参数等值电路,验证零序电压分布特征作为故障测距判据的可行性。其次,在故障区段已知的基础上,利用配网自动化系统获取有限检测点的故障零序电压信息,并通过函数拟合得到故障点上、下游区段的零序电压分布函数。最后,求解两区段零序电压分布函数的联立方程组,得到故障点位置。仿真和现场数据的测试结果表明,该方法的测距精度较高,且可以利用现有设备实现,具有良好的经济性。

Fault location technology can greatly improve the speed of fault line inspection and repair,but the existing small current grounding fault location technology in a distribution network has the problem of poor economy.Therefore,a small current grounding fault location method based on the distribution characteristics of zero sequence voltage and can be realized on the existing distribution network automation system is proposed.First,the distribution parameter equivalent circuit of a small current grounding fault is used to verify the feasibility of zero sequence voltage distribution as a fault location criterion.Secondly,based on the known fault section,the distribution automation system is used to obtain the fault zero sequence voltage information of limited detection points,and the zero sequence voltage distribution function of upstream and downstream sections of the fault point is obtained by function fitting.Finally,the simultaneous equations of the zero sequence voltage distribution function of the two sections are solved to obtain the location of the fault point.The test results of simulation and field data show that this method has high ranging accuracy,can be realized by existing equipment,and has good economy.